There has been available a system for translating a document, such as a web page or the like, written in a certain language into another language. In general, such a translation system does not translate a text embedded in an image included in a document. In order to address this point, Patent Literature 1 discloses a mechanism for sending, by a user terminal, text data included in a source of an original document or a translated document to an image server, and generating, by the image server, image data in which a text image indicated by the text data is superimposed on a background image prepared in advance to send back to the user terminal.